/**
*      author: Y_Yao
*      created: 2025-02-21 10:40:34
**/

#include<bits/stdc++.h>

#define int LL
using namespace std;
using LL = long long;
const LL LLINF = 1e18;
const int INF = 0x3f3f3f3f;
string s;
unordered_set<string> st;

void solve()
{
    cin >> s;
    if(s == "")
    {
        cout << "YES" << endl;
        return;
    }
    if(s.substr(0,5) != "choku")
    {
        cout << "NO" << endl;
        return;
    }

    for(int i = 5;i < s.size();i++)
    {
        if(s[i] == 'c')
        {
            if(i + 1 < s.size() && s[i+1] == 'h')
            {
                i++;
                continue;
            }
            else
            {
                cout << "NO" << endl;
                return;
            }
        }
        else if(s[i] != 'o' && s[i] != 'k' && s[i] != 'u')
        {
            cout << "NO" << endl;
            return;
        }
    }
    cout << "YES" << endl;
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t = 1;
    //cin >> t;
    while(t--)
    {
        solve();
    }
    return 0;
}